The invention relates in general to the field of telecommunications and more particularly to a system and method for translating telecommunications signals of span interfaces.
Three principle telecommunications data format transported on communications spans are currently used in telecommunications networks. T1 is the data format utilized within the United States. E1 is the data format utilized in Europe and other international locations. J1 is the data format utilized in Japan.
In general, a T1 span refers to the transmission medium, regenerators, and terminating equipment that carry a 1.544 megabits per second digital signal between two points on 24 channels or time slots. The transmission medium may be copper, optical, and wireless. An E1 span refers to equivalent components that carry a 2.048 megabits per second digital signal between two points on 32 channels. An E1 span can transmit 30 data channels and two signaling channels. Likewise, a J1 span refers to equivalent components used to carry a 2.048 digital signal between two points also on 32 channels. A J1 span also uses 30 channels to carry data, and uses one of the remaining channels for group signaling.
Problems of compatibility and product availability arise because of the differences between these three data formats. Although T1, E1 and J1 data formats are all designed to handle similar data transfer using similar protocols and signaling, significant differences exist between their signaling and frame synchronization as to prohibit identical hardware equipment being used for all three span types in many cases. More specifically, a telecommunications network component may be developed for a specific span type or geographical market that only allows integration with a specific span type. One example of this problem has arisen regarding modifications and upgrades to existing telecommunications networks in Japan that utilize a J1 span type, and corresponding switching and associated hardware for interfacing with such telecommunications networks. One such recent Advancement is the development of Code Division Multiple Access (xe2x80x9cCDMAxe2x80x9d) in wireless communications technologies. A CDMA upgrade dramatically increases the system capacity and service quality in wireless communications networks. CDMA transceivers replace the majority of traditional analog processing with a type of modulation that is largely applied and removed in the digital domain, and not on the basis of frequency. As a result of such advancements in wireless communications, product manufacturers and service providers are modifying existing components of wireless communications networks.
Although many of such manufacturers and service providers have more than enough market demand to justify modifying components that are specific to both E1 and T1 span types, the less widely utilized J1 span type may not be supported directly by newly developed hardware components. For example, some hardware components necessary to implement advancements such as CDMA are too expensive to justify three separate product lines for interacting with the E1, T1 and J1 span types. A problem arises as to how such developed components can be implemented in markets wherein the J1 span type is utilized.
Accordingly, a need has arisen for a system and method for translating span interfaces. The present invention provides a system and method for translating span interfaces that addresses the shortcomings of prior systems and methods.
In one aspect of the present invention, a system for switching communications signals between a first communications network and a second communications network is provided. The system includes a J1 interface coupled to the first communications network by a J1 span, an E1 interface coupled to the second communications network by an E1 span, and an interface processor in communication with the J1 interface and the E1 interface. The interface processor is then operable to translate signals formatted for the J1 span into an E1 format for transmission on the E1 span. The interface processor is further operable to translate communications signals formatted for the E1 span into a J1 format for transmission on the J1 span.
In another aspect of the invention, a method of switching communications signals includes receiving communications data from a span interface, storing the communications data in a memory according to a first memory map, receiving a request from a call processor which references the communications data by indicating an expected location according to a second memory map, translating the expected location into an actual location according to the first memory map, and responding to the request using the communications data stored at the actual location.
In yet another aspect of the present invention, a system for processing communications signals transferred between a first communications network and a second communications network is provided. A first span interface is coupled to the first communications network by a first digital communications link. The first digital communications link operable to transfer communications data in a first format. The first span interface is also operable to store the communications data according to the first format. The second span interface is coupled to the second communications network by a second digital communications link. The second digital communications link is operable to transfer communications data in a second format. The second span interface is operable to store the communications data according to the second format. An interface processor is in communication with the first span interface and the second span interface. The interface processor is configured to process communications data stored in the second format. The interface processor also includes a span convertor operable to translate the format of the communications data from the first format to the second format. This allows further processing of the communications data by the interface processor.
In yet another aspect of the present invention, a system for processing communications signals received from a communications network includes a span interface coupled to the communications network by a digital communications link. The digital communications link is operable to transfer communications data in a first format and the span interface is operable to store the communications data. A switching device coupled to the span interface includes a call processor configured to process communications data in a second format. A span interface processor then communicates with the span interface and the call processor. The span interface processor is operable to access the stored communications data and translate the accessed communications data from the first format to the second format in response to a data access request from the call processor.
In yet another aspect of the present invention, a system for processing communications signals received from a communications network includes a span interface coupled to the communications network by a digital communications link. A span interface processor in communication with the span interface is operable to receive communications data from the span interface that has been transferred to the span interface across the digital communications link. The span interface processor is operable to store the communications data in a memory according to a first memory map. The span interface processor includes a call processor which is operable to generate a call processing request that references the stored communications data by indicating an expected location according to a second memory map. The span interface processor also includes a span convertor in communication with the call processor and the memory. The span convertor is operable to respond to the request by translating the expected location into an actual location according to the first memory map and by using the communications data stored at the actual location.